CN114956065A - Amino modified graphene, preparation method thereof, amino modified graphene coating and application thereof - Google Patents

Amino modified graphene, preparation method thereof, amino modified graphene coating and application thereof Download PDF

Info

Publication number
CN114956065A
CN114956065A CN202210605350.5A CN202210605350A CN114956065A CN 114956065 A CN114956065 A CN 114956065A CN 202210605350 A CN202210605350 A CN 202210605350A CN 114956065 A CN114956065 A CN 114956065A
Authority
CN
China
Prior art keywords
amino
graphene
modified graphene
coating
amino modified
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202210605350.5A
Other languages
Chinese (zh)
Other versions
CN114956065B (en
Inventor
蔡金明
陈其赞
郝振亮
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangdong Morion Nanotech Co Ltd
Original Assignee
Guangdong Morion Nanotech Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Guangdong Morion Nanotech Co Ltd filed Critical Guangdong Morion Nanotech Co Ltd
Priority to CN202210605350.5A priority Critical patent/CN114956065B/en
Publication of CN114956065A publication Critical patent/CN114956065A/en
Application granted granted Critical
Publication of CN114956065B publication Critical patent/CN114956065B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/182—Graphene
    • C01B32/194—After-treatment
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/08—Anti-corrosive paints
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention provides amino modified graphene, a preparation method thereof, an amino modified graphene coating and application thereof, and particularly relates to the technical field of corrosion prevention. The amino-modified graphene is formed by the lateral covalent bridging of amino and carboxyl at the edge of graphene, so that the dispersibility of graphene in a solvent is improved; the amino containing lone pair electrons can form secondary covalent bonding with carboxyl on the edge of the graphene oxide without hydroxyl and epoxy groups, transverse bridging butt joint is constructed, pi-pi interaction of delocalized pi electrons enhances the interaction of upper and lower layers of graphene, finally, the amino modified graphene which is longitudinally closely stacked and transversely covalently bridged and stacked layer by layer is obtained, and the thickness of the amino modified graphene which is stacked layer by layer is reduced.

Description

Amino modified graphene, preparation method thereof, amino modified graphene coating and application thereof
Technical Field
The invention relates to the technical field of corrosion prevention, and particularly relates to amino modified graphene, a preparation method of the amino modified graphene, an amino modified graphene coating and application of the amino modified graphene coating.
Background
Graphene is a very potential anticorrosive material, and has attracted extensive attention in the field of anticorrosion. Mainly due to the following characteristics of graphene: has an ultra-large specific surface area, canThe external corrosive medium is effectively shielded; layered SP of graphene 2 The hybrid exhibits excellent mechanical and tribological properties. As the geometric pore diameter of the six-membered ring of the graphene is only 0.064nm and even smaller than the very small helium Van der Waals diameter (0.28nm), the monolithic defect-free graphene can effectively shield the direct penetration of water molecules, oxygen and other corrosive media.
Graphene is a quasi-two-dimensional structure, can be stacked layer by layer in the coating, effectively hinders the diffusion of corrosive medium, and the dissolution rate of the metal substrate can be effectively reduced when the ultra-fast electron conductivity also makes graphene as anticorrosive coating. Due to the existence of functional groups such as hydroxyl groups and epoxy groups on the surface of the graphene oxide, the thickness of the single-layer graphene oxide is larger than that of graphene.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
One of the objectives of the present invention is to provide amino-modified graphene to alleviate the technical problem of the prior art that the thickness of single-layer graphene oxide is larger than that of graphene due to the presence of functional groups such as hydroxyl groups and epoxy groups on the surface of graphene oxide.
In order to solve the technical problems, the invention adopts the following technical scheme:
the invention provides amino modified graphene, wherein amino and carboxyl are transversely and covalently bridged at the edge of graphene.
The second aspect of the present invention provides a preparation method of amino-modified graphene, including the following steps:
step A: carrying out first spray granulation on the graphene oxide aqueous solution to obtain graphene powder with retained edge carboxyl;
and B: preparing the graphene powder with the retained edge carboxyl into a solution, adding an amino modifier into the solution, and uniformly mixing to obtain a mixed solution;
and C: and carrying out a second spray granulation after carrying out a hydrothermal reaction on the mixed solution to obtain the amino modified graphene.
Optionally, the temperature of the first spray granulation and the second spray granulation are each independently from 180 ℃ to 250 ℃.
Preferably, in step a, the concentration of the aqueous graphene oxide solution is 0.5 wt.% to 1.5 wt.%.
Preferably, in the step a, the pH of the graphene oxide aqueous solution is 2 to 4.
Optionally, the amino modifier comprises 2-6 diaminopyridine.
Preferably, the addition amount of the amino modifier is 0.1-20 wt% of the mass of the graphene powder with retained edge carboxyl groups.
Optionally, in step C, the temperature of the hydrothermal reaction is 60 ℃ to 120 ℃.
Preferably, the hydrothermal reaction time is 0.5h-3 h.
Optionally, in step B, the mixing manner includes ultrasonic mixing.
Preferably, the time of ultrasonic mixing is 1min to 10 min.
The third aspect of the invention provides an amino modified graphene coating, which comprises the graphene powder with retained edge carboxyl, the amino modified graphene, a solvent, a dispersant and a modifier.
Wherein the amino-modified graphene is the amino-modified graphene of the first aspect or the amino-modified graphene prepared by the preparation method of the second aspect.
The graphene powder with the retained edge carboxyl is prepared in the step A of the preparation method.
Optionally, the mass ratio of the graphene powder with the edge carboxyl groups retained to the amino-modified graphene is 1: 0.1-1.
Preferably, the solvent includes an organic solvent and an inorganic solvent.
Preferably, the organic solvent comprises NMP and/or DMF.
Preferably, the inorganic solvent comprises deionized water.
Optionally, the dispersant comprises PVP and/or CMC.
Preferably, the modifier comprises PVDF and/or dopamine hydrochloride.
Preferably, the content of the dispersant is 0.1% -20%.
Preferably, the content of the modifier is 0.1-20%.
The fourth aspect of the invention provides an application of the amino modified graphene coating in metal corrosion prevention.
Compared with the prior art, the invention has at least the following beneficial effects:
according to the amino modified graphene provided by the invention, the transverse covalent bonding of the carboxyl group at the edge of the graphene oxide and the amino group is realized through amino modification, and meanwhile, the dispersibility of the graphene in a solvent is improved; the amino containing lone pair electrons can form secondary covalent bonding with carboxyl on the edge of the graphene oxide without hydroxyl and epoxy groups, transverse bridging butt joint is constructed, pi-pi interaction of delocalized pi electrons enhances the interaction of upper and lower layers of graphene, finally, the amino modified graphene which is longitudinally closely stacked and transversely covalently bridged and stacked layer by layer is obtained, and the thickness of the amino modified graphene which is stacked layer by layer is reduced.
According to the preparation method of the amino modified graphene, provided by the invention, the hydroxyl and epoxy functional groups on the surface of the graphene oxide are removed, so that the gap between the graphene and the graphene layer is reduced, and the thickness of the amino modified graphene is reduced. The preparation method has simple process and strong process controllability, and is beneficial to industrial large-scale production.
According to the amino modified graphene coating provided by the invention, the covalent bonding effect of the isolated amino of the amino modified graphene and the carboxyl functional group in the graphene with the retained edge carboxyl is utilized to realize the transverse bridging of the graphene and the graphene, so that a large-area transverse shielding area is obtained. Isolated electron pairs in the amino modified graphene can be bonded, so that the dispersibility of the amino modified graphene powder is improved; by adding a trace of micromolecule binder as a modifier, the binding force between graphene layers is further improved, and the corrosion resistance of the amino modified graphene coating is improved.
According to the application of the amino modified graphene coating, the amino in the amino modified graphene coating can promote passivation of a metal surface layer to form multi-level protection through electrons generated by dissolution of a metal substrate; in addition, the group of the lone pair of electrons and delocalized pi electrons contained in the amino group forms a coordination bond with atoms on the surface of the metal substrate, so that active sites on the surface of the metal substrate are reduced, the adhesion of the coating and the metal substrate is enhanced, and the coating with excellent performance is provided for metal corrosion prevention.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a thermogravimetric plot of the graphene oxide used in example 1;
fig. 2 is an infrared spectrum of amino-modified graphene obtained in example 1;
fig. 3 is an infrared spectrum of amino-modified graphene obtained in example 2;
fig. 4 is an infrared spectrum of the amino-modified graphene obtained in example 3.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The components of embodiments of the present invention may be arranged and designed in a wide variety of different configurations.
At present, graphene is usually added into a conventional anticorrosion system as an auxiliary material, and few anticorrosion coatings are prepared by using graphene as a main material or pure graphene. The research on the reasonable internal stacking arrangement of the graphene anticorrosive coating is rare. Usually, a 'labyrinth' mixed row is constructed in the anticorrosive coating in a small-amount adding mode, and the starting point is to increase the penetration free path of the corrosion medium and slow down the penetration speed of the corrosion medium. The use of graphene oxide as a filler is the most desirable layered layer-by-layer stack structure, but there is also infiltration of corrosive media through the interlayer porosity.
The invention provides amino modified graphene, wherein amino and carboxyl are transversely and covalently bridged at the edge of graphene.
According to the amino modified graphene provided by the invention, the transverse covalent bonding of the carboxyl group at the edge of the graphene oxide and the amino group is realized through amino modification, and meanwhile, the dispersibility of the graphene in a solvent is improved; the amino containing lone pair electrons can form secondary covalent bonding with carboxyl on the edge of the graphene oxide without hydroxyl and epoxy groups, transverse bridging butt joint is constructed, pi-pi interaction of delocalized pi electrons enhances the interaction of upper and lower layers of graphene, finally, the amino modified graphene which is longitudinally closely stacked and transversely covalently bridged and stacked layer by layer is obtained, and the thickness of the amino modified graphene which is stacked layer by layer is reduced.
The second aspect of the present invention provides a preparation method of amino-modified graphene, including the following steps:
step A: carrying out first spray granulation on the graphene oxide aqueous solution to obtain graphene powder with retained edge carboxyl;
and B: preparing the graphene powder with the retained edge carboxyl into a solution, adding an amino modifier into the solution, and uniformly mixing to obtain a mixed solution;
and C: and carrying out a second spray granulation after carrying out a hydrothermal reaction on the mixed solution to obtain the amino modified graphene.
According to the preparation method of the amino modified graphene, provided by the invention, the hydroxyl and epoxy functional groups on the surface of the oxidized graphene are removed, so that the gap between the graphene and the graphene layer is reduced, and the thickness of the amino modified graphene is reduced. The preparation method has simple process and strong process controllability, and is beneficial to industrial large-scale production.
Graphene oxide (graphene oxide) is an oxide of graphene and can be represented by GO for short.
Optionally, the temperature of the first spray granulation and the second spray granulation are each independently from 180 ℃ to 250 ℃.
The temperature determination of the first spray granulation and the second spray granulation is determined according to the thermogravimetric curve characteristics of the graphene oxide used.
Optionally, the amino modifier comprises 2-6 diaminopyridine.
The structural formula of the 2-6 diaminopyridine is shown as the following formula (1).
Figure BDA0003670407770000061
As can be seen from the formula (1), the amino contains a lone pair of electrons and a delocalized pi electron group, four extra-nuclear electrons exist in the outer-layer orbit of a nitrogen atom in the amino, three of the electrons form covalent bonds with H, C atoms, but one lone pair of electrons which does not form covalent bonds still exists, and the quasi-six-membered ring structure shows a delocalized pi bond effect similar to that of a graphene carbon six-membered ring, so that pi-pi conjugation is favorably formed with graphene.
Preferably, in step a, the concentration of the aqueous graphene oxide solution is 0.5-1.5 wt. -% ]
In some embodiments of the present invention, the concentration of the aqueous graphene oxide solution is typically, but not limited to, 0.5 wt.%, 0.6 wt.%, 0.7 wt.%, 0.8 wt.%, 0.9 wt.%, 1.0 wt.%, 1.1 wt.%, 1.2 wt.%, 1.3 wt.%, 1.4 wt.%, or 1.5 wt.%.
Preferably, in the step a, the pH of the graphene oxide aqueous solution is 2 to 4.
Preferably, the addition amount of the amino modifier is 0.1-20 wt% of the mass of the graphene powder with retained edge carboxyl groups.
When the addition amount of the amino modifier is less than 0.1 wt.%, only a small amount of graphene is subjected to amino modification, and a large amount of non-modified graphene still exists, so that the large-area barrier network is not constructed conveniently, and the corrosion resistance is reduced; when the addition amount of the amino modifier is more than 20 wt.%, the addition of the excessive amino modifier can increase the gap between the graphene layer and the anticorrosive coating, reduce the compactness and reduce the anticorrosive performance.
In some embodiments of the present invention, the amino modifier is typically added in an amount of, but not limited to, 0.1 wt.%, 0.5 wt.%, 1 wt.%, 3 wt.%, 5 wt.%, 7 wt.%, 9 wt.%, 11 wt.%, 13 wt.%, 15 wt.%, 17 wt.%, or 20 wt.%.
Optionally, in step C, the temperature of the hydrothermal reaction is 60 ℃ to 120 ℃.
During hydrothermal reaction, the graphene oxide edge carboxyl and one amino group of 2-6 diaminopyridine undergo a condensation reaction to form a C-N bond and simultaneously generate a water molecule, and an additional amino group is obtained, so that the condensation reaction with other graphene oxide edge carboxyl groups is facilitated, and a large-area anticorrosion interface is constructed; in addition, epoxy groups on the surface of the graphite oxide can also generate a hydroxyl group while forming a C-N bond by a ring-opening reaction with the amino modifier. Mainly reacts with carboxyl functional groups under the hydrothermal condition of 85 ℃.
In some embodiments of the present invention, the temperature of the hydrothermal reaction is typically, but not limited to, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃ or 120 ℃.
Preferably, the hydrothermal reaction time is 0.5h-3 h.
In some embodiments of the present invention, the hydrothermal reaction time is typically, but not limited to, 0.5h, 1h, 1.5h, 2h, 2.5h, or 3 h.
Optionally, in step B, the mixing manner includes ultrasonic mixing.
Preferably, the time of ultrasonic mixing is 1min to 10 min.
In some embodiments of the invention, the time of the ultrasonic mixing is typically, but not limited to, 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min, or 10 min.
The third aspect of the invention provides an amino modified graphene coating, which comprises the graphene powder with retained edge carboxyl, the amino modified graphene, a solvent, a dispersant and a modifier.
Wherein the amino-modified graphene is the amino-modified graphene of the first aspect or the amino-modified graphene prepared by the preparation method of the second aspect.
The graphene powder with the retained edge carboxyl is prepared in the step A of the preparation method.
According to the amino modified graphene coating provided by the invention, the covalent bonding effect of the isolated amino of the amino modified graphene and the carboxyl functional group in the graphene with the retained edge carboxyl is utilized to realize the transverse bridging of the graphene and the graphene, so that a large-area transverse shielding area is obtained. Isolated electron pairs in the amino modified graphene can be bonded, so that the dispersibility of the amino modified graphene powder is improved; and trace micromolecular binder is added to serve as a modifier, so that the binding force between graphene layers is further improved, and the corrosion resistance of the amino modified graphene coating is improved.
A labyrinth barrier layer is constructed by adding the graphene powder with the edge carboxyl and the amino modified graphene, and corrosive media such as water molecules and oxygen are isolated by utilizing the intrinsic characteristic of the graphene, so that the corrosion resistance is achieved.
Optionally, the mass ratio of the graphene powder with the edge carboxyl groups reserved to the amino modified graphene is 1: 0.1-1.
When the mass ratio of the graphene powder retaining the edge carboxyl to the amino-modified graphene is greater than or less than 1:0.1, the modified graphene oxide and the graphene retaining the edge carboxyl are difficult to achieve bonding matching, and the redundant non-modified graphene or modified graphene is not beneficial to constructing an ideal anticorrosion interface.
Preferably, the solvent includes an organic solvent and an inorganic solvent.
Preferably, the organic solvent comprises NMP and/or DMF.
NMP refers to N-methyl pyrrolidone, which is an organic substance with a chemical formula of C 5 H 9 NO, colorless to light yellow transparent liquid, slightly ammoniacal odor, is miscible with water in any proportion, is dissolved in various organic solvents such as ether, acetone, ester, halogenated hydrocarbon, aromatic hydrocarbon and the like, and is almost completely mixed with all the solvents.
DMF refers to N, N-dimethylformamide, which is an organic compound having the chemical formula C 3 H 7 NO, colorless transparent liquid. Is not only one kindThe solvent is a chemical raw material with wide application and is also an excellent solvent with wide application. Except halogenated hydrocarbon, the additive can be mixed with water and most organic solvents at will, and has good dissolving capacity for various organic compounds and inorganic compounds.
Preferably, the inorganic solvent comprises deionized water.
Optionally, the dispersant comprises PVP and/or CMC.
PVP refers to polyvinylpyrrolidone, is mainly used as an oil dispersant, and is used for promoting graphene dispersion and avoiding graphene agglomeration.
CMC means carboxymethyl cellulose, mainly used as a water system dispersing agent, wherein carboxyl on the carboxymethyl cellulose brings negative charges to the surface of graphene, an electric double layer is formed on the surface of the graphene, when two graphene particles are close to a diffusion layer phase and interpenetrate, the like charges repel each other, the graphene particles are forced to separate, and thus the dispersed graphene particles are stable.
Preferably, the modifier comprises PVDF and/or dopamine hydrochloride.
PVDF is polyvinylidene fluoride, a highly non-reactive thermoplastic fluoropolymer. It can be synthesized by polymerization of 1, 1-difluoroethylene. The modified graphene coating is used in an amino modified graphene coating, mainly plays a role in adjusting viscosity, and is favorable for coating construction due to proper viscosity.
Dopamine hydrochloride is an organic matter with the chemical formula of C 8 H 12 ClNO 2 White needle crystals or crystalline powder; is easily soluble in water, soluble in methanol and hot 95% ethanol, soluble in sodium hydroxide solution, and insoluble in ether, chloroform, and benzene; no smell, slightly bitter taste. When the dopamine hydrochloride is used in the amino modified graphene coating, the dopamine hydrochloride mainly plays a role in enhancing the adhesion force between graphene layers, and the graphene coating is prevented from peeling off.
Preferably, the content of the dispersant is 0.1% -20%.
Preferably, the content of the modifier is 0.1-20%.
In some embodiments of the invention, the dispersant is typically present in an amount of, but not limited to, 0.1%, 1%, 5%, 10%, 15%, or 20%; the modifier is typically present in an amount of, but not limited to, 0.1%, 1%, 5%, 10%, 15%, or 20%.
The fourth aspect of the invention provides an application of the amino modified graphene coating in metal corrosion prevention.
According to the application of the amino modified graphene coating, the amino in the amino modified graphene coating can promote passivation of a metal surface layer to form multi-level protection through electrons generated by dissolution of a metal substrate; in addition, the group of the lone pair of electrons and delocalized pi electrons contained in the amino group forms a coordination bond with atoms on the surface of the metal substrate, so that active sites on the surface of the metal substrate are reduced, the adhesion of the coating and the metal substrate is enhanced, and the coating with excellent performance is provided for metal corrosion prevention.
When the amino modified graphene coating is used, the metal substrate is heated to 60-100 ℃, the amino modified graphene coating is sprayed on the workpiece in a spraying mode, and then the workpiece is dried in an oven at 60-100 ℃ for 2-10 hours, so that the metal workpiece coated with the amino modified graphene anticorrosive coating is obtained.
In some embodiments of the invention, a PVDF coating is further sprayed on the amino-modified graphene anticorrosion coating, which is beneficial to isolating moisture and increasing multiple protection mechanisms, and further improves the anticorrosion performance of the coating.
The PVDF solution has the mass fraction of 0.5% -4%, and the solvent is typically but not limited to NMP.
Spraying the second layer on the metal workpiece, and drying in an oven at 60-100 deg.C for 2-10 h.
Some embodiments of the present invention will be described in detail below with reference to examples. The embodiments described below and the features of the embodiments can be combined with each other without conflict.
Example 1
The embodiment provides amino modified graphene and an amino modified graphene coating, and the specific steps are as follows:
1) the thermogravimetric curve of the graphene oxide is tested, as shown in fig. 1, the mass curve of the graphene oxide powder body at about 200 ℃ falls, and the falling of hydroxyl and epoxy on the surface of the graphene oxide under the temperature condition can be known by combining a raman test. Therefore, the dropping temperature of the hydroxyl and epoxy groups on the upper and lower surfaces of the graphene oxide, which are easy to drop, is 200 ℃. Selecting graphene oxide aqueous solution slurry with the PH of 1% in mass fraction of 2 as a raw material, setting the spraying temperature to 210 ℃, removing hydroxyl and epoxy groups which are easy to fall off on the surface of graphene oxide through spray granulation, reserving carboxyl functional groups which are difficult to fall off at the edge, reducing the single-layer thickness of the graphene oxide, and obtaining graphene powder with reserved carboxyl at the edge.
2) Dissolving the graphene powder with the edge carboxyl remained, which is obtained in the step 1), in deionized water, stirring and dispersing, selecting 2-6 diaminopyridine as an amino modifier, adding 3% of 2-6 diaminopyridine according to the mass ratio of the powder, and carrying out ultrasonic treatment for 5min to obtain a mixed solution.
3) Carrying out hydrothermal reaction on the mixed solution at 85 ℃ for 2H, wherein one-OH is dropped from a carboxyl group at the edge of graphene, one H ion is dropped from one amino group of 2-6 diaminopyridine, covalent bonding modification of the amino group and the carboxyl group is realized, and one part of water is generated.
4) Carrying out spray granulation on the solution obtained after the hydrothermal reaction in the step 3) at the temperature of 210 ℃ to obtain amino modified graphene powder.
5) Mixing the graphene powder with the edge carboxyl reserved and obtained in the step 2) and the amino modified graphene powder obtained in the step 4) according to the ratio of 1: 0.5, taking NMP as a solvent, PVP as a dispersing agent, dopamine hydrochloride and the like as a small-molecular binder, wherein the addition amount of the PVP dispersing agent is 0.5%, the addition amount of the dopamine hydrochloride is 0.1%, and the amino modified graphene coating with the solid content of 3% is obtained.
As shown in FIG. 2, the infrared spectrum of GO is 1500cm -1 There is no C-N stretching vibration peak, and after amino modification, a C-N stretching vibration peak appears at 1500cm-1, because amino and carboxyl generate condensation reaction to replace-OH group in carboxyl to generate C-N stretching vibration peak.
Example 2
The embodiment provides an amino-modified graphene and an amino-modified graphene coating, which are different from embodiment 1 in that the hydrothermal temperature in step 3) is 75 ℃, and infrared spectroscopy is performed on a solution after the hydrothermal reaction, and the result is shown in fig. 3, and the rest of raw materials and steps are the same as those in embodiment 1, and are not described again.
As can be seen from FIG. 3, the infrared spectrum of the sample hydrothermal at 75 ℃ was 1500cm -1 The peak intensity of C-N stretching vibration is reduced. This is mainly due to the reduced amount of C-N covalent bonds formed by the condensation reaction of amino groups with carboxyl groups to replace the-OH functionality in the carboxyl groups.
Example 3
The embodiment provides an amino-modified graphene and an amino-modified graphene coating, which are different from embodiment 1 in that the temperature of spray granulation in step 2) and step 4) is 150 ℃, and infrared spectroscopy is performed on the obtained amino-modified graphene, the result is shown in fig. 4, and the rest raw materials and steps are the same as those in embodiment 1 and are not described again.
As can be seen from FIG. 4, 3339cm representing the C-O oscillation peaks of hydroxyl groups-OH and epoxy groups of graphene oxide -1 And 1216cm -1 And a strong vibration peak still exists at the position, which indicates that most of hydroxyl and epoxy groups on the surface of the graphene oxide are not peeled off.
Example 4
The present embodiment provides amino-modified graphene and an amino-modified graphene coating, which are different from embodiment 1, in step 1), the mass fraction of the graphene oxide aqueous solution is 1%, and the remaining raw materials and steps with a pH of 4 are the same as those in embodiment 1, and are not described herein again.
Example 5
The embodiment provides amino-modified graphene and an amino-modified graphene coating, which is different from embodiment 1 in that the addition amount of 2-6 diaminopyridine in step 2) is 0.1%, and the rest raw materials and steps are the same as those in embodiment 1 and are not described herein again.
Example 6
The embodiment provides amino-modified graphene and an amino-modified graphene coating, which is different from embodiment 1 in that the addition amount of 2-6 diaminopyridine in step 2) is 20%, and the rest raw materials and steps are the same as those in embodiment 1, and are not described herein again.
Example 7
The embodiment provides amino modified graphene and an amino modified graphene coating, and is different from embodiment 1 in that two kinds of powder in step 5) are prepared according to the following weight ratio of 1:0.1, and the rest of the raw materials and the steps are the same as those in example 1, and are not described again.
Example 8
The embodiment provides amino modified graphene and an amino modified graphene coating, and is different from embodiment 1 in that two kinds of powder in step 5) are prepared according to the following weight ratio of 1: 1, and the rest of the raw materials and the steps are the same as those in example 1 and are not described again.
Comparative example 1
The comparative example provides an EP resin anticorrosive paint which comprises phenolic epoxy resin, chlorinated rubber epoxy resin, reactive diluent, titanium dioxide, acetylene black, auxiliary agent, epoxy resin curing agent and curing accelerator.
Test example 1
The amino-modified graphene coatings obtained in examples 1 to 8 and the EP resin anticorrosive coating obtained in comparative example 1 were subjected to corrosion performance tests. The test method is as follows:
step 1: a304 stainless steel plate is selected as a substrate, fine sand paper is used for polishing, and then acetone and absolute ethyl alcohol are used for ultrasonic alternate cleaning for 3 times, and the substrate is dried at 60 ℃ for standby.
Step 2: and heating the cleaned metal substrate to 80 ℃, directly spraying the metal substrate on a workpiece in a spray gun spraying mode, and drying the workpiece in a drying oven at 100 ℃ for 5 hours to obtain the metal workpiece coated with the coating.
And step 3: and (3) taking NMP as a solvent and PVDF as a solute, preparing a PVDF solution with the mass fraction of 2%, spraying a second layer on the metal workpiece coated with the coating obtained in the step (2), and drying in an oven at 80 ℃ for 5 hours to obtain the metal workpiece with the anticorrosive coating.
And 4, step 4: firstly, two scratches are carved on the surface of a metal workpiece with an anticorrosive coating in an intersecting way, then salt spray corrosion resistance tests are carried out, and salt spray test results of a plurality of groups of samples in 50h, 100h, 200h and 300h are observed.
Test results show that when the EP resin anticorrosive paint provided by the comparative example 1 is subjected to salt spray for 50 hours, corrosion spots begin to appear on a workpiece, the corrosion spots gradually diffuse from the scratch along with the passage of time, and a large number of corrosion spots appear; after the salt spray corrosion resistance test for 300h, the workpiece obtained in the embodiment 1 has only corrosion spots at the scratch part and has no corrosion spots at other places; after the salt spray corrosion resistance test of the workpiece obtained in example 2, besides the existence of corrosion spots at the scratches, small corrosion spots also exist at the positions except the scratches.
The workpiece obtained in example 3 has more corrosion spots after the test of 300h, and the corrosion of the chemical traces is more serious, which is mainly attributed to that the hydroxyl and the epoxy belong to hydrophilic functional groups, and the copper hydroxyl and the epoxy can also have a certain moisture absorption effect to perform bonding reaction with the amino functional group of 2-6 diaminopyridine, so that the gap between graphene layers is enlarged, and a corrosion medium can be diffused in a larger transverse gap.
Test example 2
The amino modified graphene coating obtained in example 1 is subjected to a corrosion performance test, which is different from test example 1 in that the cleaned metal substrate is heated to 150 ℃ in step 2, and the rest steps are the same as those in test example 1, and are not described again.
The results show that there are some small bubbles on the coating surface when sprayed at 150 ℃, and the graphene layers are in a laterally stacked arrangement with poor order, which is mainly due to the swelling and weakening of self-assembly ability caused by solvent volatilization. The salt spray corrosion resistance test result shows that a sample of the workpiece obtained in the step 3 has a large number of corrosion spots after 200 hours, and the corrosion spots are generated uniformly at the positions of the huge parts of the bulges.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. Amino-modified graphene, characterized in that at the edges of graphene amino groups are covalently bridged with carboxyl groups in the lateral direction.
2. The preparation method of amino modified graphene according to claim 1, comprising the following steps:
step A: carrying out first spray granulation on the graphene oxide aqueous solution to obtain graphene powder with retained edge carboxyl;
and B: preparing the graphene powder with the retained edge carboxyl into a solution, adding an amino modifier into the solution, and uniformly mixing to obtain a mixed solution;
and C: and carrying out a second spray granulation after carrying out a hydrothermal reaction on the mixed solution to obtain the amino modified graphene.
3. The method of manufacturing according to claim 2, wherein the temperatures of the first spray granulation and the second spray granulation are each independently 180 ℃ to 250 ℃;
preferably, in step a, the concentration of the aqueous graphene oxide solution is 0.5 wt.% to 1.5 wt.%;
preferably, in the step a, the pH of the graphene oxide aqueous solution is 2 to 4.
4. The method of claim 2, wherein the amino modifier comprises at least one of 2-6 diaminopyridine, semicarbazide, phenylenediamine, and aniline trimer;
preferably, the addition amount of the amino modifier is 0.1-20 wt% of the mass of the graphene powder with retained edge carboxyl groups.
5. The preparation method according to claim 2, wherein in the step C, the temperature of the hydrothermal reaction is 60-120 ℃;
preferably, the hydrothermal reaction time is 0.5h-3 h.
6. The method according to claim 2, wherein in step B, the mixing comprises ultrasonic mixing;
preferably, the time of the ultrasonic mixing is 1min to 10 min.
7. An amino-modified graphene coating, which is characterized by comprising the graphene powder with the retained edge carboxyl groups described in claims 2 to 6, the amino-modified graphene described in claim 1, and a solvent, a dispersant and a modifier.
8. The amino modified graphene paint according to claim 7, wherein the mass ratio of the graphene powder with the retained edge carboxyl groups to the amino modified graphene is 1: 0.1-1;
preferably, the solvent includes an organic solvent and an inorganic solvent;
preferably, the organic solvent comprises NMP and/or DMF;
preferably, the inorganic solvent comprises deionized water.
9. The amino-modified graphene coating of claim 7, wherein the dispersant comprises PVP and/or CMC;
preferably, the modifier comprises PVDF and/or dopamine hydrochloride;
preferably, the content of the dispersant is 0.1% -20%;
preferably, the content of the modifier is 0.1-20%.
10. Use of an amino-modified graphene coating according to any one of claims 7 to 9 for metal corrosion protection.
CN202210605350.5A 2022-05-30 2022-05-30 Amino modified graphene, preparation method thereof, amino modified graphene coating and application Active CN114956065B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210605350.5A CN114956065B (en) 2022-05-30 2022-05-30 Amino modified graphene, preparation method thereof, amino modified graphene coating and application

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210605350.5A CN114956065B (en) 2022-05-30 2022-05-30 Amino modified graphene, preparation method thereof, amino modified graphene coating and application

Publications (2)

Publication Number Publication Date
CN114956065A true CN114956065A (en) 2022-08-30
CN114956065B CN114956065B (en) 2023-09-26

Family

ID=82956745

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210605350.5A Active CN114956065B (en) 2022-05-30 2022-05-30 Amino modified graphene, preparation method thereof, amino modified graphene coating and application

Country Status (1)

Country Link
CN (1) CN114956065B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115368757A (en) * 2022-09-01 2022-11-22 安徽嘉阳新材料科技有限公司 Preparation process of high-strength high-barrier high-thermal-stability modified graphene powder

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104445163A (en) * 2014-11-14 2015-03-25 中国航空工业集团公司北京航空材料研究院 Preparation method of carboxylated graphene
CN104445155A (en) * 2013-09-17 2015-03-25 中国科学院大连化学物理研究所 Carboxyl functionalized graphene material and preparation method thereof
CN104555996A (en) * 2014-07-28 2015-04-29 南京新月材料科技有限公司 Preparation method and application of aminated graphene film
CN105885563A (en) * 2016-06-29 2016-08-24 德阳烯碳科技有限公司 Composite coating and preparation method thereof
CN106946246A (en) * 2017-04-27 2017-07-14 山东金城石墨烯科技有限公司 A kind of preparation method of amination graphene
CN108373149A (en) * 2018-03-15 2018-08-07 常州恒利宝纳米新材料科技有限公司 The preparation method of industrial amination graphene
US20180261402A1 (en) * 2015-09-18 2018-09-13 Toray Industries, Inc. Graphene dispersion, process for producing same, process for producing particles of graphene/active material composite, and process for producing electrode paste
US20210328221A1 (en) * 2018-10-08 2021-10-21 University Of Wollongong Dispersible edge functionalised graphene platelets
CN114162811A (en) * 2021-12-13 2022-03-11 四川大学 Carboxylated graphene oxide and preparation and application methods thereof

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104445155A (en) * 2013-09-17 2015-03-25 中国科学院大连化学物理研究所 Carboxyl functionalized graphene material and preparation method thereof
CN104555996A (en) * 2014-07-28 2015-04-29 南京新月材料科技有限公司 Preparation method and application of aminated graphene film
CN104445163A (en) * 2014-11-14 2015-03-25 中国航空工业集团公司北京航空材料研究院 Preparation method of carboxylated graphene
US20180261402A1 (en) * 2015-09-18 2018-09-13 Toray Industries, Inc. Graphene dispersion, process for producing same, process for producing particles of graphene/active material composite, and process for producing electrode paste
CN105885563A (en) * 2016-06-29 2016-08-24 德阳烯碳科技有限公司 Composite coating and preparation method thereof
CN106946246A (en) * 2017-04-27 2017-07-14 山东金城石墨烯科技有限公司 A kind of preparation method of amination graphene
CN108373149A (en) * 2018-03-15 2018-08-07 常州恒利宝纳米新材料科技有限公司 The preparation method of industrial amination graphene
US20210328221A1 (en) * 2018-10-08 2021-10-21 University Of Wollongong Dispersible edge functionalised graphene platelets
CN114162811A (en) * 2021-12-13 2022-03-11 四川大学 Carboxylated graphene oxide and preparation and application methods thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115368757A (en) * 2022-09-01 2022-11-22 安徽嘉阳新材料科技有限公司 Preparation process of high-strength high-barrier high-thermal-stability modified graphene powder

Also Published As

Publication number Publication date
CN114956065B (en) 2023-09-26

Similar Documents

Publication Publication Date Title
EP2135313B1 (en) High performance, high durability non-precious metal fuel cell catalysts
US4781980A (en) Copper powder for use in conductive paste
WO2021036797A1 (en) Method for preparing polytannic acid-coated high activity aluminum powder or silicon powder
WO1998029358A2 (en) Surface modified carbonate materials
CN101232963A (en) Copper fine particle dispersion liquid and method for producing same
CN102326213A (en) Metal thin film production method and metal thin film
CN114956065A (en) Amino modified graphene, preparation method thereof, amino modified graphene coating and application thereof
CN108031302A (en) A kind of Bipolar Membrane and preparation method thereof
CN109081334B (en) Amidation modified graphene oxide and preparation method and application thereof
CN113234342B (en) Amino acid grafted graphene oxide filler, preparation method thereof and application of filler in water-based epoxy zinc-rich coating
CN108929616B (en) Metal substrate graphene modified long-acting anticorrosive paint and preparation method thereof
CN108727947A (en) A kind of graphene oxide hydridization anticorrosive paint and preparation method
CN107828309B (en) Dispersion used for graphene anticorrosive paint and preparation method thereof
CN107488329B (en) Method for large-scale preparation of aqueous graphene epoxy resin nanocomposite
CN114621654A (en) Water-based epoxy zinc-rich primer and preparation method and application thereof
KR101533034B1 (en) Reduced graphene oxide, preparing method thereof, and ink including the same
CN115975475B (en) Modified graphene water-based anticorrosive paint and preparation method and application thereof
CN115678384B (en) Water-based resin coating composition and preparation method thereof
CN115651485B (en) Water-based paint composition
CN111057421A (en) Graphene metal anticorrosive paint for primary equipment in coastal region and preparation method
WO2023074652A1 (en) Composition and coating material
CN111892468B (en) alpha-AlH3/Al2O3/C60Double-shell structure compound, synthesis method and application
US20070082137A1 (en) Catalytic coatings, method for forming the same, and their application
CN102532954A (en) Preparation method of epoxy resin grafted montmorillonite filler
CN112723855A (en) Laser engraving preparation method and application of graphene-ceramic composite electrode array

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant